Separating the chemical fractions from these Yew bark samples was a difficult and slow process. It required skill and intuition by the researchers, using equipment that can now be found only in museums.
Research on the extracted chemicals was arduous and nearly every chemical turned out to be so toxic that they killed every cell, not just cancerous ones. One promising compound needed a name long before its structure was determined. They simply named it from the source, “Taxus” with the ending for alcohol, “ol” without any real consideration. “Taxol” was found to have already been trademarked in the 1930’s by a French company for a laxative product. However, Bristol Meyers Squibb was able to purchase the trademark and convince the Patent and Trademark office that a common laxative trademark should now apply to an anticancer drug.
Research stalled for some time for even more reasons. Supply was acknowledged to be a challenge. Taxol solubility in water was described by one researcher as being equivalent to that of brick dust. It was not clear that Taxol could be administered to patients. Severe hypersensitivity in some clinical patients and failures as an anti-leukemic drug nearly stopped research on this chemical.
Taxol displayed some promise as an anticancer agent in 1971. However, there was great reluctance to even harvest enough for clinical trials. The Pacific Yew tree is not common. Each tree could supply about 2 kilograms of bark. 12 kilograms of bark was needed to produce one half gram of Taxol. The Yew tree dies after stripping the bark.
In 1977, an order for 7,000 pounds of bark was made. This meant killing 1,500 trees, scattered in patches over millions of acres of old growth forests in the Pacific Northwest. This coincided with and became enmeshed in the debate over the spotted owl habitat. The need for natural remedies and medicinal herbs conflicted with conservationists and brought considerable notoriety to Taxol.
Taxol was found to cause regression of mammary tumors in 1978. The next year, it was found that the Taxol mechanism was unique. Previous anti-cancer compounds killed cancer cells by inhibiting the production of the building blocks that are needed for the cell to divide. Taxol stimulates the production of the building blocks such that the cells cannot coordinate for cell division.